Ethan Allen capsize: Lake George

[Stephen Ditmore]

Here's a link to today's New York Times article on the capsize of the Ethan Allen:
http://www.nytimes.com/2005/10/03/nyregion/03boat.html?th&emc=th
(you might have to create an account for yourself, but it's very quick & painless).

Presumably the M/V Ethan Allen was certified to carry passengers under Subchapter "T". Does anyone know where further information can be found concerning:


Was a simplified stability test, as called for at http://www.washingtonwatchdog.org/documents/cfr/title46/part178.html#178.330 ever performed?
Was the vessel certified for 49 passengers? On what basis?
Are the calculations available, perhaps using a Freedom of Information Act request?
Were engine vents located below the gunwale? For the purpose of the test, was the freeboard taken to the gunwale or to the vents?
Could the engine compartment have flooded by backflooding the exhaust?
Will there be an investigation?
Which Coast Guard Marine Safety Office has jurisdiction?

Note concerning my background: I was involved in preparing Coast Guard certification related materials in 1992-1993 for a similar boat in Miami, the "Ruddy Duck", which served as a water taxi to Fisher Island. My recollection is that it was certified for somewhere between 29 and 40 passengers (I'm thinking it was 29). Also, I think we made a modification to raise the engine vents.

[yipster]

no further info on your questions, just on more:

.what is the pilots story?

[cyclops]

It sounds, by reading the article, like bad luck. Full load of passengers, many on one side looking at the shore, Captain sees a sudden need to turn to the side that has few people on it, over she goes in 2 or 3 seconds. Few cruise Captains maintain a balanced load. Fact of life.

[KCook]

There was one report that the bow was seen to be riding low in the water. But I have not seen that verified, or any more details.

Kelly Cook

[FAST FRED]

To be certified by the USCG this boat was supposed to pass a stability TEST.

Sand bags , of 150lbs per person , for desired load are line up against ONE side of the vessel.
The vessel is certified to the number of 150lb pax that reduce the freeboard by half.

The story of a large boats wake may be what ATE the other half of the freeboard.

FAST FRED

[CDBarry]

According to the cited article the boat was not Coast Guard inspected, but rather certified by the New York parks department. If Lake George is not navigable waters capable of interstate commerce, Coast Guard doesn't have jurisdiction.

[D'ARTOIS]

The most important question is, for what task the boat was designed for: are there any pictures, and can somebody come up with some drawings?
A boat can capsize in a tight turn at high speed if the distributed weights are unfavourable high above the waterline; why was it necessary to avoid a passing by boat's wake?

We cannot give an answer just based on an article in a daily - those reports are mostly "colored" and often amateurish and inadequate.

Don't jump on any conclusion(s) without knowing the exact details, although, it is a strange and sad occurence.

CDBarry's comment might be right - in Europe, any vessel that carries paid passengers should be subject to a strain of safety-measurements and related tests, unimportant on what sort of waters.

[taobsu]

http://graphics8.nytimes.com/images/2005/10/04/nyregion/04boat.xlarge1.jpg

http://graphics8.nytimes.com/images/2005/10/03/nyregion/03boat2.jpg

http://www.timesunion.com/center/graphics/front1004ethanallen.jpg


Here is an article from New York Times. (

Commercial Boats Overseen by a Small Office
By SEWELL CHAN and AL BAKER

The roughly 275 commercial boats that operate in New York State waters - from sightseeing-cruise vessels on the Finger Lakes to freight-towing tugboats on the Hudson River - are overseen by a small state office that is charged with licensing, inspecting and certifying a wide array of watercraft central to the state's tourism and freight industries.

Life jackets must be provided, but passengers are not required to wear them. Boat operators have to demonstrate "a thorough knowledge of seamanship" and renew their licenses annually, but a recertification examination is required only once every 10 years.

The boats are inspected once a year, yet unannounced visits rarely if ever occur. There are three inspectors for the entire state, part of a staff of about a dozen in the regulatory office: the marine unit of the State Office of Parks, Recreation and Historic Preservation.

Federal investigators will be exploring this oversight system in the coming months as they delve into the deadly capsizing of a sightseeing boat on Lake George on Sunday, trying to determine whether safety rules were violated and, perhaps, whether the system itself is adequate to ensure passenger safety. Yesterday, the National Transportation Safety Board began an inquiry into the accident, which killed 20 elderly passengers.

But already, some elected officials and boating-safety experts were saying that several areas of regulation - licensing of captains, inspections of vessels and the rules governing life jackets - needed to be re-examined.

"Those are issues we're going to be discussing, certainly," said Assemblywoman Teresa R. Sayward, a Republican whose district includes Warren County, where the accident occurred. "Unfortunately, it takes a tragedy to start looking at regulation sometimes."

Assemblyman Roy J. McDonald, a Republican whose district includes the northeastern shore of the lake, said: "Water safety has been underregulated, and I blame the Legislature, as opposed to the enforcement agencies. In the past, the public has asked, 'Why do we need four or five sheriff's boats on the lake?' Now you know why."

Much is still unclear about the sunken boat, the Ethan Allen, and its pilot. State officials said yesterday that they had turned over copies of inspection and licensing reports to the federal safety board but declined to release them publicly, saying they would wait for the investigation to be completed.

However, a picture of the boat's operations emerged from public records and interviews.

The Ethan Allen, a 38-foot vessel with a white fiberglass hull, was built in 1966 by Dyer Boats of Warren, R.I., a leading builder of power boats, yachts and dinghies. It was licensed for tours and dinner cruises, with a capacity of 50 people, including 48 passengers and the vessel's captain.

Under the license, an additional crew member must be on board if there are 21 or more passengers, but even though 47 passengers were aboard on Sunday, the pilot was the only crew member.

The Ethan Allen passed its last inspection on May 20, but state officials declined to say whether any deficiencies were cited at the time. Officials at Shoreline Cruises, which has six cruise boats including the Ethan Allen registered with the State Department of Motor Vehicles, declined to answer any questions about the operation of the boat.

The boat's captain, Richard Paris, 74, was a New York state trooper from 1956 to 1981. He received his master's license in 1986, has renewed it each year since then and took a recertification examination in 1996, state officials said.

Boat operators must pass a practical exam, which requires them to undock a boat and steer it safely, among other tasks. Operators are also tested on their knowledge of fire and emergency drills - and on what to do if someone falls overboard.

Officials said they knew of no past problems with Mr. Paris's performance. "We have no indication that he was anywhere but where he should have been," said Larry Cleveland, the Warren County sheriff, who spoke with the captain shortly after the accident. "In fact, we believe he was maneuvering to get himself through these waves, or wakes, or whatever we're dealing with."

After any marine accident on waterways under federal jurisdiction, unlike Lake George, the Coast Guard has the operator tested for alcohol or drugs, said Anthony Palmiotti, director of continuing education at the State University of New York Maritime College, in the Bronx.

Sheriff Cleveland said he did not ask Mr. Paris to take such a test because there was no reasonable cause to do so. "If I had had any suspicion whatsoever," he said, "I would have made that call and made sure he was tested."

The state's marine unit, the Bureau of Marine and Recreational Vessels, has limited resources to conduct inspections beyond its regular licensing and certification process, said John M. Prenderville, who worked at the parks office from 1975 until 1995, when he retired as a deputy commissioner. The bureau distributes money to counties and towns to pay for boat-safety training and police boats, he said.

In addition to the oversight by the parks office, the Lake George Park Commission - a panel created in 1961 to oversee the lake and surrounding forests - is supposed to oversee the use of watercraft. It has a small law-enforcement arm.

The use of life jackets, or other floatation devices, will almost certainly be a focus of the safety board's investigation. Few, if any, passengers on the Ethan Allen wore the devices.

The use of flotation devices was the subject of a symposium the safety board sponsored in August 2004.

"The whole issue of life preservers is something we have to talk about," Ms. Sayward said. "Whenever I get on a boat, they always tell you where they are, but the issue is, how do you get them? Unless you had a very slow leak, it would be difficult to get all of them out and onto people."

About 80 percent of all deaths in recreational boating could be prevented if life jackets were worn, said Charles A. Sledd, president of the National Association of State Boating Law Administrators.

At the very least, all tour boats should give a safety talk and explain to passengers, before the boat undocks, that they have the option of wearing a life jacket, said Virgil H. Chambers, the executive director of the National Safe Boating Council, an advocacy group in Manassas, Va.

[Corpus Skipper]

This is a tragic occurrence, but I can already see the fallout. MAKE PFDs MANDATORY will be the battle cry, to which I say PHOOEY! I am a grown adult and can make my own educated decisions about my own safety. I also deck hand on a party boat offshore of Port Aransas, so I know first hand that no one wants to wear them anyway. As the article states, we give a safety briefing before departure showing the locations of PFDs as well as how to don them. Beyond that, it's up to each individual if they should wear them, as it should be. I've seen one person put one on all summer. Don't let this tragedy be a tool for the safety nazis to slap one more regulation on us all. We have too much allready.

[SolomonGrundy]

It is my understanding that there were no required crewmen aboard this vessel on this trip. Only the pilot and not the additional 2 crewmen. I've heard conflicting reports on this but that's the word I have.
The company has a few (4 or 5 ) other boats and they have all been ordered not to leave the dock until things are straightened out.

[SolomonGrundy]

It is truley tragic & my heart goes out to the loved ones who have lost those dear to them.

[Stephen Ditmore]

I share the last sentiment. I've spent a signifigant portion of my working life on stability issues in order to prevent accidents like this one, and I have strong feelings about it.

I think the press is focusing on the wrong issue. These people died in the main not due to lack of an additional crewmember or lack of life jackets. They died from lack of sufficient stability. This is a technical issue, and it is the responsibility of naval architecture as a profession to provide sound guidance as to what constitutes a safe boat (and standards for safe loading & operation within a clear design envelope).

Over the last decade or so there has been a move to simplify stability screening for passenger vessels under 65 feet of non-extreme design. The simplified test is 46 CFR 178.330 in the United States code of Federal Regulations. I have not used this test in its most current form. Has anyone else out there? Is it valid, and does it yield an appropriate minimum value? WOULD THE ETHAN ALLEN HAVE PASSED loaded with 47 adult passengers?

I'm seriously considering submitting a Freedom of Information Act request to find out if such a test was performed on the Ethan Allen or a sistership. I'm happy to hear that the Transportation Department is now testing a sistership and asking the technical questions, and I hope that what is learned can be incorporated into 46 CFR 178.330 in such a way that it is still simple, but is further clarified, can be consistantly applied, and can guide designers of both recreational and passenger boats, especially with respect to maximum capacity (relative to intact stability).

[fatpat]

here's a link to an article in a Toronto paper. they cite heavier passengers but this might be even more significant (from the article):

"Investigators also were to look at excess weight from recent changes made to the boat, such as the addition of a larger engine and replacing a canvas canopy with a wood-Fiberglas design."

here's the link:

http://www.thestar.com/NASApp/cs/ContentServer?pagename=thestar/Layout/Article_Type1&c=Article&cid=1128507347079&call_pageid=968332188492&col=968705899037&t=TS_Home

[cyclops]

I saw a photo of the ship on TV this morning and her empty free board looked like 12" to 18". Can not believe that. But she looked low and squatty. A 74 year old pilot? What are the probabilities he will have reflex and decision altering medicins? I am 68 and have removed any ideas of being a volunteer boat captain due to the high risk of light headiness. Most public conveyences are operated by people with problems. They work for less money.

[marshmat]

It is truley tragic & my heart goes out to the loved ones who have lost those dear to them. I second that. Hopefully there will be a full investigation into this. At the moment the media are relying mostly on speculation. This incident reminds me of one in B.C. earlier this year involving a chartered houseboat that capsized. That one was due to gross overloading; I doubt the cause here is so simple. Hopefully we'll all learn some lessons from this....

[KCook]

I agree Stephen. Seems very odd to me that so much attention is being given to the PFD and crew requirements. EVEN on boating message boards! I seriously doubt that an additional crew member would have prevented the accident.

Kelly Cook

[mmd]

This issue is also being discussed over on the WoodenBoat forum, and the commentary focuses on PFD's and operator competence quite a bit. This is a bit of what I wrote on that forum:

"Folks, with the greatest of respect for your concerns about whether or not wearing PFD's should be mandatory on commercial tour boats, that issue is, IMHO, secondary to the real question here.

Why did the boat capsize in the first place?

There should be no way in God's green earth that a commercial tour boat should be able to be capsized by the wake of another, larger, boat in a lake, near shore, on a clear, calm summer's day. None. Zip. Nada.

Legislate that an accurate linesplan is required for all commercial passenger-carrying hulls - if not available from the designer/builder, measure the boat. Require that such boats have calculated ultimate stability and conditional stability in multiple loading conditions, including worst case scenario. Make it a requirement of licesure for operating a tour boat that the captain understands the principles of stability and can understand a stability booklet. Confirm the boat's displacement and centre of gravity by conducting an inclining experiment prior to issuing a certificate of seaworthiness. Prove that the boat has sufficient stability to be safe in all operating conditions. Then inspect the boat on a regular schedule to enforce compliance. Legislate that any changes to the boat arrangements, structure, or powering requires re-certification.

Draconian? Yes, definitely. But if it keeps someone's Granny from drowning in her wheelchair, it is worth the effort, IMHO.

(rant over...) "

[Stephen Ditmore]

I hadn't noticed CDBarry's earlier post. He's a Coast Guard naval architect, and he would know. I would still submit, however, that 46 CFR 178.330 is the applicable standard that the State of New York should have been using (and should employ now as one useful tool in its investigation).

[JTom]

Hi I am new to this board and am trying to learn more about the simplified stability test.

Does anyone know of the background of the simplified stability tests Specifically the development of the formula used within the regulations? Has there been anything written about it's development or critical of it? Has anyone evaluated it's adequacy in terms of ensuring safety? I'd like to know where the 6 came from in the formuala below and the basis for that number as opposed to using another?

Also can someone explain to me how does stability associate to capacity on a passenger vessel? What other factors need to be considered if one was to review a passenger vessel and it's allowable number of passengers?

Mp = (W) (Bp)/6; or

Mw = (P) (A) (H)

where:

Mp = passenger heeling moment in kilogram-meters (foot-pounds);

W = the total passenger weight using 72.6 kilograms (160 pounds) per passenger, or, if the vessel operates exclusively on protected waters and the passenger load consists of men, women, and children, 63.5 kilograms (140 pounds) per passenger may be used;

[tom28571]

Does it really matter whether the passengers were wearing lifejackets or whether there was one or two crewmembers or how old the captain is or whether there was a wake from a passing boat, etc? The plain fact is that the boat capsized in benign circumstances while carring fewer than rated capacity of passengers. Seems to me like they are looking for a scapegoat.

This is a case where the operative body governing such boats in New York state did not do their job properly. We, me included, chafe at the intrusions in our lives by government. Here, more and certainly more effective control should been exercised.

The only passenger carrying boat I have been concerned with fell under USCG jurisdiction and stability testing was carried out which determined how many passengers, what level they could be on on the boat, how many could be on one side on the upper deck and where the boat was allowed to operate when carrying passengers. If any such testing was ever done on this boat, the regs need revision.

Of course, I may be wrong but things like this should not happen even is all the things they are pointing to all occured at the same time..

[marshmat]

Latest news on the investigation:
MICHAEL VIRTANEN
ASSOCIATED PRESS

LAKE GEORGE, N.Y.—A tour boat nearly identical to the one that capsized Sunday, killing 20 elderly tourists, became unstable after weight equivalent to just 10 people was placed at the edge of the vessel, the American National Transportation Safety Board said yesterday.

The stability test found the Ethan Allen unsuited to handle the weight of the 48 people on board, said the safety board's Mark Rosenker. He would not say how many passengers the boat could have safely held.

During the test of the Ethan Allen's sister vessel, the de Champlain, investigators placed three 55-gallon (208-litre) barrels at the boat's edge and filled them with water, at which point the boat became unstable.

The combined weight of the barrels was just over 1,400 pounds, or the equivalent of 10 people as defined by Coast Guard weight standards that assumes an average weight of 140 pounds per person.

"We terminated the test because it was unsafe at that point,'' Rosenker said. (Toronto Star, Oct. 6/05)

Perhaps this will provide some insight into the cause of the wreck....

[CDBarry]

On another recent small passenger vessel tragedy:

http://www.sname.org/sections/chesapeake/papers/05-9-ppt.pdf

[sal's Dad]

A closer look at the Ethan Allen's design - Starting with a top-of-the-line (if 40 year old) Dyer 40 bare hull: http://www.dyerboats.com/dyer40.html

http://www.dyerboats.com/images/40quintina2_420.jpg

Then "innards and superstructure would have been fitted on by the first buyer, a Groton, Conn., company that used it for tours of the submarine base there."

Next "have decking installed at the height of the gunwales and have windows and a roof extending high above the waterline" http://timesunion.com/AspStories/story.asp?storyID=405641&category=CAPSIZE&BCCode=HOME&newsdate=10/7/2005

Add seating benches (http://www.timesunion.com/specialreports/capsize/ , link to "Ethan Allen", lower left).



And you have this shallow, top-heavy boat; a former skipper "said the boat handled well, but he always was careful to make sure passengers were evenly spaced, especially when it was windy. The best way to avoid an imbalance... was to make sure tourists stayed in their seats." http://www.freep.com/news/nw/captain5e_20051005.htm
http://nandotimes.nandomedia.com/ips_rich_content/BOAT_OVERTURNED_NYJM30110051638.jpg


Add 47 elderly passengers, average weight 174 lbs: http://www.heraldonline.com/24hour/nation/story/2783480p-11400440c.html


For contrast, a tourboat I am familiar with on the coast of Maine - a converted 50' Navy utility boat, for 64 passengers. The photo shows a tourist sitting on a continuous high bench just inside the gunwale - the deck is about 5' BELOW the gunwale, midships. If a passenger were to be thrown from a bench by rough seas, s/he would land "safely" in the bottom of the boat.
http://longreachcruises.com/images/Sagadahocclose.jpg

Sal's Dad

[JTom]

The SNAME Report is quite interesting. I'd like to know how the new recommended weight was determined. I also wonder if that weight change would apply to formulas used for stability tests on other vessels. -JT

[safewalrus]

Just remember one thing - 47 people on a 38 foot boat is asking for trouble! It's OK if they all SIT STILL! But passengers being people and as in all these kind of tragedies they move around! especially if they are landlubbers (you wouldn't get that many seamen on a boat that size they'd get off or wouldn't get on! No good blaming the skipper hes told it will take that many people, he's earning his living, as faras he's concerned these people are cargo - the worst bloody cargo you can get IT MOVES OF IT'S OWN FREE WILL!

[Stephen Ditmore]

An inclining test (or simplified version) has now been performed by NTSB. Here's the New York Times report:
http://www.nytimes.com/2005/10/06/nyregion/06devels.html

This pretty much confirms my suspicion that the Ethan Allen just plain lacked sufficient intact stability to carry 47 adult passengers, and I agree with Tom L. (a few posts previous) that NYS has screwed up (in a way that the Coast Guard would not have on an USCG inspected vessel). But I'm now more satisfied that the NTSB <http://www.ntsb.gov/Surface/marine/marine.htm> and NYS <http://nysparks.state.ny.us/boating/services.asp> are on the right track in their response.

Concerning the viability of the simplified test, Newsday notes today that the NTSB had already recommended that the Coast Guard abandon the 140 pound per person weight assumption and instead use 174 pounds as the assumed weight of each person. It will be interesting to see if the Coast Guard makes this change to 46 CFR 178.330 when it is next republished.

It might be helpful going forward if there were a quick screening that could be done to all the passenger vessels regulated by 50 states based on published particulars. Those that fared poorly in the initial screening could then be singled out for further analysis. ABYC has a formula for capacity intended for boats under 26 feet, but one has to purchase the booklet and/or be a member. It's ABYC H-5, last revised in 2003. Since I'm not familliar with it, I don't know if the variables have any relationship to intact stability.

[skiffman]

A lot of people seem to think the boat company is at fault here & have all sorts of ideas and remedies etc. If there is a complete investigation made we may never hear the conclusions reached by what ever authority conducts it? Often times it seems to take months before a decision is made & publicly announced. It's a shame things have to move so slowly & the injured parties deserve better treatment than to wait so long for closure.

[cyclops]

The way the reports are reading. No one with be reponsible because they were understaffed or not properly trained in capacity determination. Would like to, could have, should have, on and on. Maybe in 2 to 5 years we can give it to the US Coast Guard. They inspect all our 6 passenger speed boats and 13 passenger boat. We are a non-profit museum. How the hell can a state inspection be of a lower standard than a federal standard for a ride for profit business?

[D'ARTOIS]

Here again plays the "moneygame" between the insurance companies an important role. The process of investigation is very importan and will finally play an important role in he trial against the owners/operators that will be definately a result of this tragedy.
An unsuitable boat has been used w/o the necessary tests to perform a task it has not been designed for. The boat rides high and is clearly top-heavy. Look at the first picture where she clearly shows no draft.

[dougfrolich]

ABYC for boats under 26' recomendations as of 7/04 state that:

H-5.6.3.1 Maximum weight capacity is determind by obtaining the boats cubic capacity below the static floatplane(defined as somthing similar to the margin line) converting this value to the weight of water it would displace,subtracting the boats weight, and permitting one pound of load capacity for every seven pounds of remaining displacement.

5.6.3.2.1 The number of persons shall not exceed the value determined by dividing the quantiy of 32, plus the posted persons pound capacity, by 141 and rounding up or down to the nearest whole number.

[Stephen Ditmore]

Thanks Doug. I'm more interested in preventing this in future than I am in the recriminations game, so let me offer a few suggestions on what I think the states should do from here.

A. All commercial passenger vessels in the U.S. (whatever the regulatory authority) should be stability tested (or retested) using 46 CFR 178.330 (or whichever Coast Guard standard is applicable), modified by assuming 174 pounds per passenger (as NTSB recommends) by the end of 2010.

B. The following vessels should be retested (as above) before reentering passenger service in the spring of 2006:


Vessels that have never been properly tested & rated.

Vessels that have added weight at or above the main deck since their last test.

Vessels due for a test according to existing practice.

Vessels whose rated passenger capacity exceeds that calculated using ABYC H-5 (modified by assuming 174 pounds per passenger instead of 141).

Plot all state regulated passenger craft on a graph with LWL*BWL^3 on the x-axis and rated # of passengers on the y-axis. I suggest the 20% of craft with the highest y/x ratio should be retested before summer 2006. (LWL=waterline length, BWL=waterline beam).

Those are my ideas for screening. NTSB could take the first step by requesting the information necessary for screening be submitted to them by all the states & territories of the U.S. by the end of 2005.

[dougfrolich]

I think those are excellent suggestions.
In terms of prevention I think that operators must appreciate the implications of adding weight (and in some cases removing) to an existing vessel--which I would guess is the most common cause of capsize.

[cyclops]

How do we handle the modifications done to the vessel by any one at any time for any reason. Ex.--- different power------added structure. Or even repairs from any collision?

[SolomonGrundy]

Does anyone know if this vessel was subject to a weight and stability certificate? I know that after the "Cape Rouge II" capsizing, the Canadiens require a sign off for most structural and powerplant modifications. Especially mods to the top house. I'm just wondering if this vessel (or any vessel) must have met such requirements.

[FAST FRED]

Our current boat is a Navy 50 launch "LUCY" that is used for costal cruising.

The Navy rates the boat for 150 ! sailors , so I'm sure she is fantasticly stiff downrated to only 64.

This boat was of course built with Fire Retardant resin (Both Navy & USCG required) .

What is interesting is she has full foam flotation.

A collar about 2 ft wide and 3 ft deep runs all around the boat under the side deck.

Simply chopping a hole in the bottom will only flood the boat , not sink the boat.

I have been told this is so the liberty launches /utilities could be used as emergency life boats.

Should the carrier be hit hard , the boats would be brought up the elevators and buldozed over the side.

Sure its 75 ft down to the water and the DD 6-71 might go thru the bottom , but the hull would still float and be capable of being a raft.

The Uniflite hull is 4 inches thick in spots to accomidate such abuse (LLoyds only drops boats 15 ft ,not 75,for their tests) , yet only weighs 22,500 lbs empty, ready to hoist aboard.

These hulls with great running engines are sometimes avilable for about $25,ooo and make great costal cruisers.
I have seem one or two there the hull was completly gutted and they do fine offshore with suitable fuel tanks, and flopper stopers.

Will be doing the Erir Canal-Trent Severne Georgan Bay next June -July if anyone wants to look.

FAST FRED

[Stephen Ditmore]

How do we handle the modifications done to the vessel by any one at any time for any reason. Ex.--- different power------added structure. Or even repairs from any collision?

The two factors most related to stability are waterline beam and center of gravity. While overall displacement plays a role in the calculations, it mostly cancels out by the time all is said and done, except as it influences waterline beam and VCG. Modifications that add weight at or above the deck are most likely to adversely influence VCG, so I suggest those are the ones that should trigger a new stability test (though certainly the removal of ballast or other weight low in the boat should also be taken account of, as you suggest).

One way to perform a quick check is to check the roll period of the boat. This is particularly useful if the previous roll period is known, which is why the roll period at the time of the test should be recorded (best if tanks are either empty or pressed full at times of all roll period tests).

[dougfrolich]

Again Stephen has an imprtant point.
All vessels carring passengers for hire should have a stability booklet as part of it documentation, with previously recorded charactoristics known, then simple tests can be performed after modifications have been made to check if stability has been degraded. ( I would hope however, if an owner wanted to enclose the upper deck of his head boat that he would consult a NA for guidence BEFORE the modification). It is simple enough to determin GMt by inclination why not require it at the time of certification, and after modifications--Owners and operator will benefit from gaining real understading of the effects of adding weights.
A very interesting report can be found in the 2004 Transactions published by SNAME on page 385 "The loss of the Beth Dee Bob".

[cyclops]

And how do we control the company who ORDERS staff to do as told and say nothing or pack their bags? Penalties seem to always let the dirt bags off with no admitting of guilt or restitution. Oh yes, a fine, which some consider a payoff settles everything. Very often it does not cover damages or staff expenses. A backround check of the naval authority would probably reveal most are ex shipping owners or their ex. employees. Wolves guarding the sheep.-----------------After thought. How about all the staff being the survivors or relatives of survivors. No bigger a conflict of interest than owners.

[sal's Dad]

Perhaps some good will come of this tragedy - in Maine, there is a first discussion of the safety of inland passenger vessels: http://pressherald.mainetoday.com/news/state/051010ferry.shtml

An excerpt:

To pilot a passenger vessel on fresh water, a person must pass a 25-question test administered by the fish and wildlife department. The license can be renewed through the mail each year for $4.

Hawley, the Frye Island ferry operator, says he has been troubled by the absence of state standards for freshwater passenger boats since long before the accident on Lake George. He says the apparent legal vacuum gives him little authority to address what he considers an unsafe situation on his vessel.

Hawley says it is common practice to load the 65-foot boat so tightly that cars must fold their mirrors to fit and passengers, who ride in their vehicles, could not escape in case of a fire or sinking.

<snip>
Hawley says he took his concerns to the Frye Island Board of Selectmen, which oversees the municipal-owned ferry. He says the selectmen did not acknowledge a safety problem and didn't want to reduce the number of cars per ferry because it would require paying to run an additional boat.

Perhaps The Coast Guard could develop "Uniform Standards" which could be adopted by the states... Enforcement could be by state DOT, with inspections contracted out to USCG or private consultants.

[dougfrolich]

I don't think that the problem with the Ethan Allen was with the pilot of the vessel, and I do not think that having another crew member on board would have done much. It really seems to me to be a problem with the vessel. If it was capable at one time of carrying 49 passengers, it certainly was far from capable on the day of the accident for some reason, and that is the issue that needs to be resolved. More stringent licensing for the pilot would not have prevented this from happening IMHO.

[CDBarry]

Note that the Coast Guard is strictly limited in its jurisdiction, not only by Congress, but by various provisions of the Constitution, as interpreted by the Supreme Court. Jurisidiction over non-navigible (in interstate commerce) waters is very well settled and established to be the responsibility of the states or localities in question.

[cyclops]

Can them, because they are not doing the job RIGHT!! What is more important. Incompetance or saving lives and business property?

[FAST FRED]

"Can them",,, if you mean Congerss , I'm all with you.

The "Hooligan Navy" USCG used to do a good job , but to recruit they had to become "more" than a lifeboat service .

Now there just armed marine police , ZEROING out their budget would be a great Idea , but don't expect to see the cash saved ....
congress keeps all unspent funds for their re election campains.

See the new "energy " bill for hundreds of millions in campain spending at taxpayer expense.

"Pork" the lifeblood of incumbants

FAST FRED

[sharpii2]

A lot of people seem to think the boat company is at fault here & have all sorts of ideas and remedies etc. If there is a complete investigation made we may never hear the conclusions reached by what ever authority conducts it? Often times it seems to take months before a decision is made & publicly announced. It's a shame things have to move so slowly & the injured parties deserve better treatment than to wait so long for closure.

It seems that the imformation about this incident is all over the map. When I first read about this, the boat was 40ft long and 10ft wide. Then I heard it was 38ft long. And now I hear its 39.7ft long and 12ft wide. And that's not all. I heard the boat had been sold in one form then modified in 1997. The modifications were:

1.) the deck was raised up to the level of the lowest freeboard. (how high it was before I am not clear on. I'll assume that it was 9 to 12in above the load waterline and moved to about 30in above the load waterline.)

2.) A bigger engine was added. (how much bigger was not said. Nor was the size of the original. (I'll assume that the original was around 50hp, continuous and the new engine double that.)

3.) Trimming ballast of approximately 1,000lbs was added in the form of lead bricks. Whether they were fixed somehow or just set in place is left to the imagination, as well as their placement along the length of the boat. (My guess is that they were intended to conterweight the heavier new engine. And I'll assume that they were just set in place, because with the boat's intended use, they were not likely to move)

4.) The fabric awning was replaced with a rigid plywood/fiberglass one. (I'll assume that the original weighed around 150lbs total including the uprights and that the new one weighed around 400lbs, not including the uprights, and was placed about 18in higher.)

So that's all I know. ...or all I think I know.

It would be nice if the reporters weren't in such a hurry and took a little more time gathering thier facts. Perhaps they can start teaching that in journalism school (which is subsidised at taxpayer expense.)

It appears to me, after doing a scaled scetch of the cross section and calculating where the VCG was likely to be, that the boat had a range of stability of at least 40deg. with a full load.

It also appears that the passengers were well aware of the danger of moving too many to one side. At least one passenger was reported (in the "Detroit Free Press") of telling the other passengers to distribute their weight by siting evenly on both sides of the boat. Another passenger, sensing the tippiness of the boat, refused to even take the trip.

Due to the reported nature of some of the injuries to the pasengers, such as severe bruises and broken bones, it appears to me that the passengers on the high side either slid or were flung to the low side after the boat started to tip.

My guess is that what happened was:

1.) that there was a large wake,
2.) that the skippered tried to turn into it to cut it, (he may have turned too sharply)
3.)That the boat, due to the sharp turn, already started tipping,
4.) that the boat failed to turn quick enough to cut the wake evenly causeing the boat to tip even more (maybe as much as 30deg),
5.) that the passengers on the high side started sliding in their seats (many probably weren't strong enough to hang on) to the low side, and
6.) that due to this sudden redistribution of weight to the low side, the boat continued to to tip until it capsize.

I would caution against against regulating our fool little heads off over this, because it may cause us to end up with boats that are as impractical as they are 'safe'. What would it take to make this boat stable enough to have even twenty passengers all on the low side? Such a requirement may not be realistic, but should be carefully investigated in case it is. There may be a reasonable cost way of accomplishing this. And there may not be.

The fact that this boat seems to have operated without incident for at least seven years after it was modified disrturbs me. And that it appears that the skipper was well aware of the boat's limited stability (which may explain why it was able to operate without accident for so long) disturbs me even more.

Did he ever bring this up to his boss?

Was there an anonamous way for him to report this to the proper authorities if his boss didn't listen?

I think these two questions are the really important ones. Especially the second one.

If the answer to the second question was 'yes', then even the small bureaucracy that was available would have been in a possiton to correct the problem without inspecting every boat in its jurisdiction.

Making the answer to the second question a 'yes' would be a very good place to start when we talk about new 'needed regulations'.

Bob

P.S.-My personal opinion is that the passenger deck was set too high.

[cyclops]

What would happen on a modern Carribean cruise if everyone came up on the main deck and all went to one side? NOTHING. It happens on many ships as the ship leaves the pier. The state inspectors are completly understaffed. Who is left after Harry goes for the coffee and doughnuts?

[sharpii2]

What would happen on a modern Carribean cruise if everyone came up on the main deck and all went to one side? NOTHING. It happens on many ships as the ship leaves the pier. The state inspectors are completly understaffed. Who is left after Harry goes for the coffee and doughnuts?

Very good point.

But the two are not the same. Not even close.

With a cruise ship I bet you have at least ten tons of accomodation for each passenger on board. By 'accomodation' I mean cabin space, toilets, showers, beds, public great rooms, galleys, stores, ect. ect.

I think you will find that the passengers on your average cruise ship make up such a small, small proportion of the ship's total displacement that their weight, no matter where it is centered, has little effect.

With a small passenger boat such as the ETHAN ALLEN which has no accomodations for it's passengers other than seats, the passengers and crew are likely to make up as much as 1/3rd to 1/2 the boat's total loaded displacement.

I think a small passenger boat such as the ETHAN ALLEN has more in common with your typical aluminum fishing skiff than it does with any cruise ship.

Bob

[Enrico]

The Ethan Allen appears to have fallen through the stability tests otherwise required by the Coast Guard because it did not operate on navigable water where federal jurisdiction applies.

:!: If you are looking for information about the Ethan Allen capsize, the investigation or insights, check out the Ethan Allen Investigation Blog (http://tcattorney.typepad.com) If you want to weigh in on the cause of the Ethan Allen accident, assign responsiblity for what happened or ask question, check out this Ethan Allen Investigation Wiki (http://ethanallenlakegeorge.jot.com/WikiHome) which can be edited by anyone.

No one intended this accident to happen but several players could have prevented it with a relatively minor amount of effort. Taking people out on the water is a heavy responsibility for any company. When we examine what was done to ensure the safety of Ethan Allen passengers, the answer thus far appears to be nothing. There was no dockside safety briefing (http://tcattorney.typepad.com/wrongfuldeath/). There were no life jackets where they can be used by passengers. The attempted compliance by Shoreline Crusies with minimal or non-existent New York Department Of Parks and Recreation regulations is hardly where most people would set the safety bar for a commercial enterprise taking people out on the water.

[Enrico]

By the way, this is the most intellegent discussion I have seen on the internet or in the press concerning this accident. If we are to take a step forward on issues of passenger safety on tour boats, we need an open and honest discussion about these issues. We can't merely rely on the NTSB report and nod our heads.

[cyclops]

The Cunard line in 100 years has sank more large un-sinkable liners than any of you know. With a loss of thousands. The same laws of design and survival still apply today. Any business always improves the profits first, then anything else later. Or they will not be in business later.

[Enrico]

Interesting observation about profits. However, at some point the 'market' demands safety. In order to make profits, safety becomes a market differentiator. For instance, look at automobiles. In the 1970s, there was literally no marketing message that had anything to do with safety. In the 1980s, the fed considered mandating airbags which was technology available. Auto manufacturers said that no one would pay the extra $750-$1,250 in price. They stalled a decade on this erroneous premise. It turned out the market would demand safety. Now, safety is a key marketing component of autos.

How do we make this happen in the tour boat / ferry industry? Clearly, an accident such as the Ethan Allen (http://tcattorney.typepad.com) presents that opportunity.

[D'ARTOIS]

I think the Ethan Allan is a perfect but bad example of re-converting a specific boat into something the original designer did not had in mind. We call this improper metaphorical use of an object, in this case a boat that has designed as a leisure one rather than being a kind of passenger ferry.
Even in the undeep Dordogne River, in the place where I live, there are some passenger vessels that go out with tourists - a similar qty to Ethan Allan - and I have observed the safety-measurements: each boat was tested by loading it with filled up containers as a sample weight of the passengers and pushed from starboard to larboard with sufficient freeboard to match;
Above the heads of the passengers are the lifebelts, just for grab; the boats are designed to carry loads or passengers, they resemble the old Gabares, the old transport barge of the Dordogne river.
The Dordogne is an undeep river; at most places one can wade through, but nothing is left to chances.

[sharpii2]

So far I have not been able to find out when and how far up the deck was raised. My gues3 is that was done either in 1997, when the 1st alterations were done or later. I certainly hope the boat was not delivered in that condition. My personal guess is that the deck was originally 12in above the DWL and that it was later moved to 30in above the DWL. If so, it probably raised the boat's CG by at least 5in with an 8ton passenger load.

By my calculations, based on what little I know about the boat, it would have required at least 2700lbs of ballast to bring the CG back to where it was. If she were my boat, this is what I would have done once I decided to raise the deck:

1.) Added the estimated ballast, turning my 9.5 ton boat (again, my guess) into an 11 ton boat. That way I could also make up for the imbalance of seating too. The ballast, probably 19 cuft of concrete, would be tabbed to the hull so it could not shift. The tabbing would be strong enough to withstand a 90 deg. roll.

2.) Bolted the seats to the deck, so they could not shift. This would also be strong enough to withstand a 90 deg. roll.

3.) Added strong 'arms' to the ends of the seats, so the pssengers could not slide out of them. Also strong enough to withstand a 90 deg. roll.

4.) Put cribbing under the seats to hold in place one life jacket for every seat 'place' , so that they would be in easy reach of the passengers.

My guestimation is that these additional changes would have added around $10k to the cost of the original modifications. Much of that would be spent replacing the original bench seats with ones strong enough to withstand the new loads I have specified.

This, of course, would exact another price. The boat would ride 3 to 4in deeper with my additional modifications than it did with the origininal ones. In total, according to my guestimations, the boat would be riding 5 to 6in deeper than it would have without any modifications.

This is why we designers, and wanna be's (such as myself), always say: "Don't f--- with my design." It's not just ego.

Bob

PS I think the State of New York needs to be sued as well. After all, they are paid to look after our interests, not just kowtow to their 'special interest' 'campaign contributers'.

[cyclops]

You can thank the Republicans for convincing the supreme court for ruling that police and most political governing bodies can no longer be sued for any reason.

[Robert Gainer]

The police are sued all the time. As a matter of fact the US government is also sued all the time. The law protects the government from some actions being brought against it but does not prevent all actions from being filed. However, suing the government is not the answer. Why can’t people be responsible for their own actions? The boat owner is the responsible one in this case. The captain also bears responsibility. You can’t legislate common sense and no matter how tight the regulations are some fool will find a way around them or just ignore them. Make people responsible.
Robert Gainer

[Stephen Ditmore]

It appears to me that the person responsible is Ms. Bernadette Castro, Commissioner, New York State Office of Parks, Recreation and Historic Preservation. I mailed her the attached letter a week ago (in which I reiterate the recommendations I've made here).

I would note that New York State TEACHES naval architecture at SUNY Maritime Academy. It is also home to Webb Inststitute (an entire engineering school devoted exclusively to naval architecture) and the United States Merchant Marine Academy. Stevens Institute (home of Davidson Hydrodynamics Lab, naval architecture is part of their civil engineering program, offers a masters program in transportation management) overlooks New York City from the Jersey Bank of the Hudson.

[cyclops]

If you sue the political bodies. Great. Taxes go up to make up for the settlements. Net change. Zero. They laugh all the way to the paid dinners.

[Stephen Ditmore]

As I read 46 CFR 178.330 the criteria using Beam/6 does not seam as conservative as I would think a Coast Guard rule for passenger vessels should be. The Coast Guard is apparently relying on passengers to keep their collective center of gravity in the middle third of the boat. A 4 or 5 in the denominator would sit better with me. Anyone know how the Coast Guard justifies a 6?

[sharpii2]

Interesting observation about profits. However, at some point the 'market' demands safety. In order to make profits, safety becomes a market differentiator. For instance, look at automobiles. In the 1970s, there was literally no marketing message that had anything to do with safety. In the 1980s, the fed considered mandating airbags which was technology available. Auto manufacturers said that no one would pay the extra $750-$1,250 in price. They stalled a decade on this erroneous premise. It turned out the market would demand safety. Now, safety is a key marketing component of autos.

How do we make this happen in the tour boat / ferry industry? Clearly, an accident such as the Ethan Allen (http://tcattorney.typepad.com) presents that opportunity.

Nope. Don't think so.

People drive around in cars every day. They, themselves, are pretty much 'experts'. 'Experts' not on car design, but car handling and the hazards there of. They may get on an excursion boat maybe once or twice in their lives. Once they do, like people getting on a jet liner, they are totally dependent on the captain and crew. They probably have no idea of what makes a safe boat even though, in this particular case, several sensed an unsafe one.

Air bags made it into autos only because a luxury auto company introduced them first. The other car companies then added them to their luxury models only as a counter move. I'm not so sure that issue in the end was safety rather than status. It was a good thing though.

I am highly suspicious of the idea of 'market forces' producing anything other than inflated avarice and shoddy products, if they 'produce' anything at all.
Henry Ford produced the 'model T'. 'Market forces' did not. To credit 'market forces' for anything is, in my opinion, not only abdicating credit where credit is due, but all human accountabillity as well. The fact that the ETHAN ALLEN was unsafe will, I bet you, eventually be blamed on 'market forces'.

Bob

[RANCHI OTTO]

Some time ago we have jamboized a tanker ship.
The problem of stability loss due to the new length was avoided by putting 2 sausages at the side.
It would be possible to increase the stability of such passenger vessels with 2 sausages when large modifications are foreseen

[cyclops]

You can not spend any of a companies money for any reason. You can't even have their bussiness permits withdrawn.

[Stephen Ditmore]

Yes, you can change a vessel to improve stability, which, as I've said, is primarily associated with waterline beam and low center of gravity. Whatever its stability, though, there will always need to be a maximum passenger capacity, and a way of determining said capacity.

[RANCHI OTTO]

I agree with you Stephen, but there are a lot of countries where passenger boats or vessels are overloading in such manner that only with the help of the Lord they arrive safe at destination...

I suppose that in States such dramatic accidents are very rare...

[Stephen Ditmore]

I'm aware of that, Ranchi, but thanks for mentioning it. The U.S. is at its best when it leads by example (not by preaching). If the U.S., Europe, and not insignificantly Australia, which is putting a very serious effort into good regulation, can set a standard, then our profession can point to that standard as a way to make the sea safer for everyone.

[cyclops]

How many present, small cruise boats, under 100', would pass a test that required. Full load, all on 1 side, at maximum speed, with moderate chop and cutting the wheel very quickly to a full rudder. I see no difference in safety on a Queen Mary or a small cruise ship, do you?

[RANCHI OTTO]

Cyclops, to satisfy the stability test you need only to know where find a lot of dwarfs....

[cyclops]

Probably all working in the vessel safety division with a very low overhead.

[mflapan]

Proposed new Australian Stability Standard

Dear Participants in boatdesign.net,

I have been reading the messages about the capsize of the Ethan Allen. My organization (the National Marine Safety Committee) is reviewing intact stability standards for domestic commercial vessels in Australia.

A draft of the new standard has been prepared and is currently available for public comment. It can be viewed at http://www.nmsc.gov.au/yoursay_2.htm.

A test based on the US Category T test has been used by Australian jurisdictions for 25 years quite successfully. However, as part of the review process, the Category T test has been removed.

This section has not been my project, so I am not yet aware of the rationale behind the change. That should be explained in a Regulatory Impact Statement that will be posted on our website this week.

Some changes have been proposed for Category S which also would have relevance to Category T if that were retained. These include raising the assumed weight of passengers from the current equivalent to 46kg (for Category S) to 75 kg per person for all classes of service.

In an earlier draft that retained Category T, it was proposed to calculate the passenger moment on the basis of lateral centre of gravity rather than B/6, assuming a distribution of 4 persons per m2 in the worst lateral location.

One reason why the simplified criteria are being reviewed is that, as an alternative to simplified criteria, stability may be calculated using comprehensive stability criteria (i.e. Rahola-IMO type criteria). However, the anomaly arose that a vessel would frequently pass the simplified criteria and fail the comprehensive criteria. This is inconsistent with logic. Comprehensive criteria should be the better measure of the vessel's characteristics and, if anything, the margin of safety should be built into the simplified criteria. The result of this anomaly has been that simplified criteria is often preferred BECAUSE IT WAS EASIER FOR THE VESSEL TO PASS than the comprehensive criteria. My understanding of simplified criteria is that they are intended to reduce the cost of measuring compliance, rather than the cost of achieving compliance. An analysis of the reason for the anomaly showed that the assumed passenger heeling moments were frequently very different, those for Category S and T being much less.

The proposed change to Category S means that the passenger moments are calculated in the same way for both simplified and comprehensive criteria, meaning that we are at least comparing apples with applies.

Participants in this website are welcome to comment on the draft stability standard and the regulatory impact statement. The cut-off date for comment is 10 January 2006.

Regards
Mori Flapan

[Stephen Ditmore]

I've taken a look at the standard above, and one comment I have is that it's unclear that you go to "Draft Document C6B" Chapter 5 first to calculate heeling moments before going to "Draft Document C6A" Chapter 6, the simplified stability test. This should be corrected both in the flow chart at the beginning of each document, and by referencing the appropriate C6B chapter in C6A, wherever heeling moments are called for.

Even though I'm not an Australian citizen I plan to submit a comment form before January 10 with this and other observations. Please understand that I wish to be constructive, not critical. As I've said:

Australia.... is putting a very serious effort into good regulation.
Bravo, Australia!
(see also http://www.boatdesign.net/forums/showthread.php?t=9231)

[mflapan]

Dear Stephen

Thank you for your input. Comments on the draft standard from yourself and any other participants to this forum are most welcome, notwithstanding that the person might be located outside Australia. There is no technical reason why safety should differ across borders. Variations in safety outcomes between countries are largely the result of differences in community expectations, politics and economics.

Public comment received on our draft standards is collated and reviewed by a reference group comprising both industry and government representatives. The members of the reference group are chosen for their expertise in the content of the particular standard and hopefully bring to the process an understanding of Australian community expectations and economic considerations. They make recommendations for changes to the draft to the National Marine Safety Committee, which comprises the chief executives of the various Australian Marine Authorities. The NMSC's function includes an awareness of political objectives and issues. So persons making public comment from outside the Australian arena need not be concerned that they might be remote from such issues. Public comment that provides good technical input and logic will make its mark.

Members of this forum might be interested in a presentation that was made at the Interferry 2005 Conference that was held in Greece in October. A White Paper has been prepared by the DnV Passenger Vessel and High Speed Craft working group on behalf of Interferry proposing the development of an international standard for domestic ferries. The White Paper will be submitted to IMO for its consideration. Details of the presentation can be viewed at:

http://www.interferryconference.com/confpapers/ThunesPpt.pps

Best regards

Mori Flapan

[safewalrus]

Interesting to note a local (Falmouth, Cornwall -some would say England, but the locals wouldn't!) ferry firm has decided to retest it's vessels as passenger size has increased over the last few years!

How?

by getting a lot of 'Large' (fat) people to go out in the ships, at a given time a large proportion of them will all go to one side then rush over to the other whilst the helm is put hard over! confident or what! Obviously there will be rescue boats standing by, but what a resounding way to test - proves beyond doubt that the vessel is stable (if not a lot of people will get wet!)

Thats the way to do it! None of yer silly bloody calculations! do it properly! :)

[cyclops]

Bless that ferry company and talk it up for them doing the test. Sink or swim, they deserve some Free TV coverage.--------In the USN all destroyers get the same test. Entire crew runs back and forth to check the maximum roll angle. It takes a long time to get her rolling.

[Stephen Ditmore]

I'll post the math to justify this later, but a roll period test is a good quick test. In general any boat for which the roll period, over and back, in seconds, is more than 1/3 the beam in feet, in any loading condition, is not stable enough to carry passengers for hire. This might need to be modified a little for boats with large keels or skegs that dampen the roll, but it's still a pretty good rule of thumb.

[cyclops]

I can give the roll period of the DD 519 DALY at 45 knots. Full port rudder applied from amidship by a sticking servo drive. took 3 seconds. Crew swept off, guns ripped out of their locking pins. And most important Saltwater was found later inside the stacks and the smaller safety stacks. It proves that almost any ship can self destruct. If the cold seawater had made it all the way down the safety stacks we would have vaporized in a massive steam explosion. Our original steam chests were replaced in WWII after a Kamikaze attack and replaced with those from a light cruiser. ----------------------------------------------Small, very fast destroyer on steroids.

[trouty]

:)

I'll post the math to justify this later, but a roll period test is a good quick test. In general any boat for which the roll period, over and back, in seconds, is less than 1/3 the beam in feet, in any loading condition, is not stable enough to carry passengers for hire.

Please realise- my genuine interest in this subject and the entire thread. I'm trying really hard to understand all this stability stuff.

Is it just me or does that quote above sound 'wrong'?.

If the roll period is shorter (i.e the boats stiffer, or rights faster doesn't that mean it's MORE inherrantly stable - ergo has more weight below the metacentric height, and less above?)

Should the quote read:-

In general any boat for which the roll period, over and back, in seconds, is MORE (my emphasis) than 1/3 the beam in feet, in any loading condition, is not stable enough to carry passengers for hire.

A long roll period - surely means that the vessel is less stable, ie takes longer to right itself, or has a shorter righting lever? (Gz?)

And isn't the boat with a longer righting lever (Gz?), which rights itself more quickly (is more stable) the one that SHOULD be carrying the passengers?

Confuzzled!:confused:

Likely as not I got the bull by the tits - feel free to correct me.

Many thanks in advance.

Take your books trouty and go straight to the bottom of the class...and be prepared for a long stay there! (Source - Most of trouty's school teachers...who ALL had the ability to look at the ceiling while saying this and do this!):rolleyes:

Ya gets used to it after a while!:D

Cheers!

[FAST FRED]

"How many present, small cruise boats, under 100', would pass a test that required. Full load, all on 1 side, at maximum speed, with moderate chop and cutting the wheel very quickly to a full rudder. I see no difference in safety on a Queen Mary or a small cruise ship, do you?"

None are tested to,


When we got boats thru the USCG inspection process the loads were water drums (or sand bags) lined up on a rail.

Basically the vessel could loose 1/2 the freeboard , and that weight was the pax load.
Any portholes or openings need a metal hatch cover or the freeboard only counts to the lower lip of the lowest hole.Sub T

FAST FRED

[sharpii2]

:)



Please realise- my genuine interest in this subject and the entire thread. I'm trying really hard to understand all this stability stuff.

Is it just me or does that quote above sound 'wrong'?.

If the roll period is shorter (i.e the boats stiffer, or rights faster doesn't that mean it's MORE inherrantly stable - ergo has more weight below the metacentric height, and less above?)

Should the quote read:-



A long roll period - surely means that the vessel is less stable, ie takes longer to right itself, or has a shorter righting lever? (Gz?)

And isn't the boat with a longer righting lever (Gz?), which rights itself more quickly (is more stable) the one that SHOULD be carrying the passengers?

Confuzzled!:confused:

Likely as not I got the bull by the tits - feel free to correct me.

Many thanks in advance.

(Source - Most of trouty's school teachers...who ALL had the ability to look at the ceiling while saying this and do this!):rolleyes:

Ya gets used to it after a while!:D

Cheers!

I think he meant MORE than 1/3rd the beam in ft in seconds.

Probably a brain fart. I have them all the time.:o

Also. Too much stability can be a bad thing too. If a vessel rolls to quickly, it can be very uncomfortable to be on. For example, have you ever seen a a sail boat with a keel leaving the harbor parallel to a swell without its sails up? It can behave like a mechanical bull. I saw a Flicka doing that one day and boy did it roll.

The skipper restored order soon enough. He got the sails up.

Bob

[Stephen Ditmore]

A long roll period - surely means that the vessel is less stable, ie takes longer to right itself, or has a shorter righting lever? (Gz?)

You are completely correct, Trouty. I've edited my post to read as it should. I apologize for my embarassing error.

Stephen

[trouty]

:)

You mean - theres actually some limited form of hope for me yet? ;)

Ye gads - I scare me sometimes...in that - I love to read scientific stuff - which I usually have absolutely no idea what it means - and just try n read and understand it anyway, for the heck of it.

Occasionally - (just very occasionally, mind you) - a small wee light comes on - (for a fleeting second) in a loooong dark tunnel...(usually a fast approaching freight train!).

Just once - in a very brief, what appeared lucid, moment..I swear - I once distinctly heard a penny drop somewhere...

The fact I'm actually getting a hang of some of the mumbo jumbo you guys talk - (sometimes) - actually scares me...

It's just possible - I MAY be getting to know just enough to be dangerous.;)

Luckily - I know these all too brief sentient moments, soon pass..

In the meantime - I just keep taking the pills! :p

One a these days - they are gonna let me outta my padded room...true!;) - but they said it wouldn't happen until I was 'stable' - whatever that means?
(Yes - an intentional pun, no less!)...;)

Ya see - I think I'm actually crazy rather than just plain stupid - but try telling my idiot shrink that!! :D

Cheers!

[Stephen Ditmore]

From Preliminary Design of Boats & Ships (Cyrus Hamlin, 1989), p. 70:
Natural Period, T = K(r) * beam / GM^0.5
GM = [K(r) * beam / T]^2

where:
GM = waterline beam, feet
Beam = waterline beam, feet
T = measured rolling period, seconds
Kr = a constant, preferably derived..., otherwise use .42 for fine waterplanes, .44 for average, and .46 for full (metric .76, .80, .83 respectively).
Ibid, p. 71:
A handy use of this relationship between GM and the rolling period was told to me by Jan-Olof Traung, for many years chief of the Fishing Vessel Section of the Food and Agriculture Division of the United Nations. We were in Indonesia discussing some of the perilously loaded small craft one sees in developing countries. In order to evaluate the safety of these craft quickly and on site, he used the criterion that if the rolling period of a boat was greater than the beam of a boat in yards (or meters), then the GM, and hence its stability, was questionable. For instance, if you time the rolling period of a boat with a beam of 18' (6m) as more than 6 seconds, it would be best to stay off it.

[End quote]

Substituting K(r)=0.44 and T=B/3 into:
GM = [K(r) * beam / T]^2
GM = [0.44B / (B/3)]^2
GM(req'd) = 1.74 feet
Compare to this energy criterion from §170.173:
(4) An area under each righting arm curve of at least 10.3 foot-degrees (3.15 meter-degrees) up to an angle of heel of 30 degrees
Assume the area from 0-30 degrees is triangular.
Area = 15GZ(30)
GM = GZ(30) / sin(30)
Therefore:
10.3 = 15GZ(30)
10.3/15 = GZ(30) = 0.6867
GM = 0.6867 / sin(30) = 2(0.6867)
GM(req'd) = 1.373 feet
One could work backwards from this number to a modified roll period / beam ratio as follows:
GM(req'd) = 1.373 feet
GM = [K(r) * beam / T]^2
1.373^0.5 = 0.44B / T
1.172 / 0.44 = B / T
1.172T = 0.44B
T(max) = 0.44B / 1.172 = B / 2.66
To be conservative, one could use a slightly lower estimated K(r):
GM(req'd) = 1.373 feet
GM = [K(r) * beam / T]^2
1.373^0.5 = 0.426B / T
1.172 / 0.426 = B / T
1.172T = 0.426B
T(max) = 0.426B / 1.172 = B / 2.75
I conjecture that the area under the righting arm curve from 0-30 degrees is most likely to be triangular on flush deck vessels with beam / freeboard < 6. If such a vessel has no opening below the gunwale and operates on protected waters I would be comfortable with any as loaded roll period less than B / 2.75. For other vessels I'm inclined to endorse Jan-Olof Traung's guideline without modification.

Here's why the experts are skeptical: Values for K(r) vary more than Cy Hamlin's values indicate because keels, skegs, rudders, bilge keels, stabilizer fins, other appendages, chines, and variations in hull shape can damp rolling. It's always better to use a K(r) that has been derived for an individual vessel or sistership at the time of an inclining experiment.

Here's why I like it: It's a quick check that's a heck of a lot better than nothing!

[trouty]

When you quote:-

A handy use of this relationship between GM and the rolling period was told to me by Jan-Olof Traung, for many years chief of the Fishing Vessel Section of the Food and Agriculture Division of the United Nations. We were in Indonesia discussing some of the perilously loaded small craft one sees in developing countries. In order to evaluate the safety of these craft quickly and on site, he used the criterion that if the rolling period of a boat was greater than the beam of a boat in yards (or meters), then the GM, and hence its stability, was questionable. For instance, if you time the rolling period of a boat with a beam of 18' (6m) as more than 6 seconds, it would be best to stay off it.

I presume your talking about these perilously loaded 3rd world small craft in their perilously loaded condition?

I.e. - when we are about to board som inter island ferry in indo / bali etc - we shpould do the quick calc and compare to roll period before we embark & they cast off?

Sounds plausible to me!

(course ya wouldn't catch me dead in one a them places for quids!).

Cheers!

[Stephen Ditmore]

I'm saying that, yes. I'm also saying that if the captain of the Ethan Allen had done it with passengers aboard before casting off he would have known that the boat was unstable, as loaded. If rocking the boat with passengers aboard is disconcerting to them, other ways can be found to utilize roll period testing to perform frequent checks, which could be helpful in educating everyone concerned about the chatacteristics of individual boats. Captains of small craft do not carry stability books with information to compare their loading condition against, as ships do. I think roll period testing is a valuable tool for small craft in whatever part of the world.

Since I've mentioned New York State Parks, Recreation, & Historic Preservation commissioner Bernadette Castro by name I should mention that she has replied to my letter assuring me (and other recipients of similar letters, I'm sure), that New York State is implementing the NTSB's 174 pound per passenger modification to the Coast Guard standards, and saying (in so many words) that New York State will be looking to the NTSB for further recommendations on corrective & preventative actions to be taken.

[trouty]

with what you've said Stephen.

I can't help wondering - if the test you describe couldn't be "abbreviated into a short "aid memoir" for captains to easily remember....just as they do with Navigation etc... (East is least, West is best, or...Red sky in Morning / sailors warning etc..you get the idea!).

Something "witty" that skippers can pass on - to would be boat owner / operators - that they can easily recall - when wanting to test roll period/ passenger loading.

Maybe thats something the board could all contribute too...

A witty way to memorise / immortalise Stephens quick stability test...

So - how bout it - anyone got any ideas?

Somethin about "Rockin the boat" has to be part of it, no???? (And it should rhyme to make it easey to remember - so much the better of it's funny to boot!

Cheers!

[Stephen Ditmore]

Beam in meters, the roll must be sweeter.... something like that? Might be best if it contained the notion that the roll must be FASTER, and that one measures a full period - OVER AND BACK.

For some reason a roll period test is sometimes referred to as a "sally test." I used to do this to wooden Haitien freighters leaving the Miami River stacked with clothing & bicycles bound for Haiti. We used windage area to determine a GM(req'd) for each individual boat, including the pile of bicycles on the cabintop. We'd chock docklines on center bow & stern and remove the others. Then we'd float the boat just clear of the dock and slack the lines. I'd get the whole crew to jump onto the gunwale and then back onto the dock in unison to get the boat rolling. In order to get them to coordinate effectively I found I had to do it with them. I'd then time a group of 3 full rolls, over and back, and divide by 3. I'd repeat this 5 times, throw out the highest & lowest result, and average the middle three.

[cyclops]

I was on a old steam powered double deck boat in Canada. The capitain was very non- bending on no more than about 6 of us on the upper deck.-------------------- Hindsight, he under stood the limits. We crossed several wakes at full speed and various angles in 25 to 35 mph gusts with no more than a 5 to 10 degree list.------The boat was a restored original in private ownership.--------When the tour ended, everyone lined up on 1 side to look to shore. No real list then either.

[Stephen Ditmore]

How 'bout:
Beam in meters, the roll must be sweeter + Rock & roll, don't go if it's slow. (?)

[CDBarry]

There used to be an IMO (maybe) standard for roll periods for fishing vessels. Try looking at NVIC 5-86 (or so) on the Coast Guard website. IOt was never widely used in the US as a primary requirement, but it might be interesting.

[Enrico]

There are some new pictures posted on our web site (http://tcattorney.typepad.com/wrongfuldeath/) which show a 3-D mock-up of the Ethan Allen. It is striking to me that it such a shallow draft, and with the modified canopy, it APPEARS top heavy to the naked eye. There is almsot nothing below the waterline. It look like a canoe.

Would not a good captain/boat owner question this design on sight alone? Or at least the modification of the vessel which added so much more wieght up high.

I have been on the water all my life and this vessel simply looks suspect. I can't imagine any math formula which would make this ship, with the modified canopy, stable even without passengers.

I also can't imagine a captain not noticing that the ship had a slow righting moment (which the Ethan Allen must have had) and thus might have stability issues.

[Stephen Ditmore]

I don't think the 3d model at Enrico's site is an entirely accurate representation of the Dyer 40 hull. Also, if one could always judge these things by eye, there are a lot of cruise ships that look like they might flop over on their sides at any moment.

I agree that there are reasons one might have been suspicious. Mine is feeling that the passenger rating is just plain high for that size boat. But hindsight is 20-20. The real question, as I see it, is what a professional should do if they are suspicious, and some valid, quantitative method that can be used on the spot, I think, could play a valuable role.

It's still not clear to me whether New York ever performed a Simplified Stability Proof test on the Ethan Allen or a sistership, or how the passenger rating was arrived at. It seems to me this information should be available through a FOIL request (see http://www.pbs.org/now/politics/foiamap.html). I think a big part of the burden should be on the state to show that they performed their regulatory role properly.

Enrico, do you have data from an actual test performed on the Ethen Allen or a sistership? I'd be particularly interested to know the freeboard and, if known, the full load displacement at the time of the test. How much freeboard was lost as how much weight was shifted how far with how much total weight on the deck?

[Enrico]

Stephen: I agree and have posted a comment on the issue here (http://tcattorney.typepad.com/wrongfuldeath/2005/12/3d_computer_ani.html#comment-11773591).

Here is my comment and I would ask anyone else to weigh in on what other differences they can visuallly identify...

A question has been raised at the BoatDesign.net BBS as to whether these 3D graphics are an exact replication of the Ethan Allen. I have to agree. If you look at the GUNWALE (the upper edge of a boat's sides), towards the bow, it certainly appears that there is more upward curve than on the actual pictures of the Ethan Allen. Also, the windows do look taller than in the photographs. The origin and purpose of the 3-D graphics is unclear. However, I think the graphic does offer some idea of how high the center of gravity must have been on this boat and how slow the righting moment must have been as it heeled (tilted) to either side.

Keep up the great work and discussion. I could not agree more with your thoughts about trying to find some easy vehicle for commercial boat owners (especially tour boats) to have an objective measure with which to easily gauge stability and roll moment. I would also be interested in compiling a 'red flag' list for boat operators where they might question a posted capacity limit. Must we rely exclusively on common sense?